The description relates to fluidic devices.
Many types of testing devices can be used in detecting the presence of compounds or analyzing bio-chemical reactions. For example, lateral flow assays can be performed using a lateral flow membrane having one or more test lines along its length. A fluid with dissolved reagents travels from one end of the membrane to the test lines by electro osmosis. A reader detects whether reaction occurred at the test lines, which indicate the presence or absence of certain particles in the reagents. As another example, a device with an array of micro capillaries can be used to control the flow of fluids in immunoassay processes. Reagents are positioned at various locations along the lengths of the micro capillaries so that as fluids flow in the micro capillaries due to capillary force, the fluids come into contact with the reagents. A reader monitors the sites where the reagents are located to determine whether reactions have occurred. As yet another example, micro fluidic chips can be used to perform assays by controlling the flow of fluids through various channels and chambers. The micro fluidic chips are used with an external power supply and/or pump that provide the driving force for moving the fluids.